1. Field of the Invention
This invention generally relates to methods and devices for treating nerve inflammation and damage in animals, including humans, and more particularly relates to methods and devices for treating carpal tunnel syndrome in humans.
2. Description of the Prior Art
Carpal tunnel syndrome is a condition that affects millions of people. In fact, the condition is the fastest growing condition among the list of repetitive motion disorders, which comprise over 48 percent of work related diseases in accordance with the teachings of R. M. Szabo in the article, “Carpal Tunnel Syndrome as a Repetitive Motion Disorder”, Clin. Orthop., 1998 June; (351): 78-89. The condition prevalence is approximately 3.5 cases per 1000 persons per year, as taught by D. L. Nordstrom et al. in the article, “Incidence of Diagnosed Carpal Tunnel Syndrome in a General Population”, Epidemiology, 1998 May; 9(3): 342-5.
Carpal tunnel syndrome arises from pinching or compression of the median nerve by the transverse carpal ligament and possibly the hypertrophied tenosynovium that forms the inner lining of the carpal canal. This nerve runs in the carpal tunnel, which is on the palmar side of the hand, with the ligament on top of it. The ligament holds the carpal bone together, providing stability to the hand, as shown in FIG. 1 of the drawings.
Following compression of the nerve, tingling, weakness, incoordination and pain, which is described by those afflicted as “needles and pins”, are the end result. During the early stages of the disease, anti-inflammatory drugs and modification of the behaviors or activities that lead to the disease are often prescribed. Still, most patients seek help only when the condition has worsened, and muscle atrophy and severe pain are possible. If the condition is left untreated, permanent nerve damage could be taking place.
The most common surgical intervention for this disease is to alleviate the pressure on the median nerve by releasing it from the transverse carpal ligament. This is done by open or endoscopic surgery, where the carpal ligament is incised. More specifically, in an open procedure, the skin and connected tissue above the ligament are incised, or with endoscopy, where a small incision is made at the wrist through which an endoscope is inserted. In both approaches, the median nerve is isolated and separated from the carpal ligament. The ligament is then incised and the pressure is relieved from the median nerve.
Several complications are associated with the surgery. The healing time can be prolonged, a second surgery may be necessary to dissect the ligament adhesions of the cut edges of the ligament to the nerve and surrounding tissues can further complicate the situation. Also, the inflammatory reaction to the dissected ligament can be severe. It should be realized that any time a tissue is cut, the surgeon risks cutting the wrong tissue. In addition, when the ligament is cut, a soft tissue structure that provides support to the hand's bony structure is lost, resulting in less support and stability of the hand.